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This page is written by the game's inventor, Charles Gilman.

Battle of the Diagonals

This variant is based on an idea that I've had for some time and found hard to finalise, but the story behind it goes back still further. It was in Tunnelchess, for which I first sought and found the Chess Variant pages, that I coined the use of Emperor for the 26-direction royal piece. Well when I started thinking about hex-prism board I realised that the same piece had the same number of directions on those boards. However it omitted one of that geometry's three kinds of diagonal, so I added a President omitting the Unicorn's diagonal and a Founder omitting the Bishop's one. Just I had given the Emperor a "family" of Empress-Archduke-Conqueress-Conqueror to go with the King's Queen-Prince-Princess-Princeling so I gave the President and Founder families of comrades in the form of Firstlady-Premier-Spokeswoman-Spokesman and Suffragette-Revolutionary-Dissentress-Dissenter. It eventually occurred to me that the "couples" at least - the royally-restricted, and long-range, symmetric piece following the King-Queen pattern - might be the basis of three rival armies on a hex-level board in the 3-player Honeycomb Chess style.

This idea nagged at me for a while. I could see how I could complement these pieces with the "female" piece stripped of its Rook move as the Bishop analogue, and the Rook with the "missing" diagonal added as Rook analogue, and even Pawnbrokers/Pawnbreakers/Brokerbreakers as Pawn analogues. What was not obvious to me was what might take the rôle of the Knight. Two kinds of diagonal had a path through Pawn-style front ranks anyway, unless I doubled them up. I didn't fancy giving one army Knights, one Sennights, and one Heffalumps as they would play so differently, Sennights especially being bound to single levels. Another possibility might have been compounds such as Knight+Sennight=Stalwart and Sennight+Heffalump=Sheriff, but I had not devised the latter name at the time of posting and still have yet to devise a name for Knight+Heffalump. I wondered about one- or two-step pieces using radials in the same patterns, but these seemed too weak. Then I thought of pieces with both moves, but these lacked satisfactory names at the time.

Then I read in one comment that Prince+Alibaba or Wazbaba+Fearful had the pre-existing name Pasha, and this inspired me to rename 3d and hex analogues. The variant below is the one on which I finally settled. I decided to have relatively few long-range pieces and put them right at the back, so that they cannot leave camp until a shorter-range piece has. I soon recognised the piece ratios as Shogi-like, and designed promotion accordingly.


\___/Bb3\___/ . \___
/Bb3\___/ . \___/ . \___
\___/ . \___/ . \___/ . \___Levels 1
/ . \___/ . \___/ . \___/Pe2\___ and 6
\___/ . \___/ . \___/ . \___/Mu2\___
/ . \___/ . \___/ . \___/Pe2\___/Ds2\
\___/ . \___/ . \___/ . \___/Mu2\___/
/ . \___/ . \___/ . \___/Pe2\___/
\___/ . \___/ . \___/ . \___/
/Po1\___/ . \___/ . \___/
\___/Po1\___/ . \___/
\___/Bb3\___/ . \___
/Bb3\___/ . \___/ . \___
\___/ . \___/ . \___/ . \___ Levels 2
/ . \___/ . \___/ . \___/Pe2\___ and 5
\___/ . \___/ . \___/ . \___/Kh2\___
/ . \___/ . \___/ . \___/Pe2\___/Pf2\
\___/ . \___/ . \___/ . \___/Kh2\___/
/ . \___/ . \___/ . \___/Pe2\___/
\___/ . \___/ . \___/ . \___/
/Po1\___/ . \___/ . \___/
\___/Po1\___/ . \___/
\___/Bb3\___/ . \___
/Bb3\___/ . \___/ . \___
\___/ . \___/ . \___/ . \___ Level 3
/ . \___/ . \___/ . \___/Pe2\___
\___/ . \___/ . \___/ . \___/Eu2\___
/ . \___/ . \___/ . \___/Pe2\___/Fl2\
\___/ . \___/ . \___/ . \___/Ei2\___/
/ . \___/ . \___/ . \___/Pe2\___/
\___/ . \___/ . \___/ . \___/
/Po1\___/ . \___/ . \___/
\___/Po1\___/ . \___/
\___/Bb3\___/ . \___
/Bb3\___/ . \___/ . \___
\___/ . \___/ . \___/ . \___ Level 4
/ . \___/ . \___/ . \___/Pe2\___
\___/ . \___/ . \___/ . \___/Ay2\___
/ . \___/ . \___/ . \___/Pe2\___/Pd2\
\___/ . \___/ . \___/ . \___/Ay2\___/
/ . \___/ . \___/ . \___/Pe2\___/
\___/ . \___/ . \___/ . \___/
/Po1\___/ . \___/ . \___/
\___/Po1\___/ . \___/


Each piece comprises components of the same range in two or three types of radial direction. Here is a list of the radial types with the various components in each. In this variant no pieces are Leaping as moving along a nonstandard or hybrid diagonal is hard enough to block, so that two-step moves are modelled on the Xiang rather than the Alfil.
ORTHOGONALS are directions through the faces of 3d cells, six through rectlinear faces to adjoining cells on the same level and two through hexagonal faces to the cells directly above and below. The General moves one step orthogonally and must be kept out of check, a property inherited by its compounds. The Wazbaba moves one or two steps along the same orthogonal. The Rook moves any distance along tbe same orthogonal through empty intermediate cells. The Point moves one step along either of the two orthogonals toward the face of the board furthest from its starting cell.
STANDARD DIAGONALS are directions through the edges of hex faces, six upward and six downward to cells immediately surrounding those immediately above and below. The Ferz moves one step along standard diagonals. The Fearful moves one or two steps along tbe same standard diagonal. The Bishop moves any distance along tbe same standard diagonal through empty intermediate cells. The Cross moves one step along any of the four standard diagonals toward the face of the board furthest from its starting cell.
NONSTANDARD DIAGONALS are directions along a rectilinear face between the cells at either vertical edge, six to the nearest non-adjacent cells on the same level. Nonstandard-diagonal piece are bound to a third of a single level, but all this game's compounds except the Sheikh and Tricorn have an unbound component. The Viceroy moves one step along nonstandard diagonals. The Vinnock moves one or two steps along tbe same nonstandard diagonal. The Unicorn moves any distance along tbe same nonstandard diagonal through empty intermediate cells. The Saltire moves one step along the nonstandard diagonal directly toward the face of the board furthest from its starting cell.
HYBRID DIAGONALS are directions through the rectilinear faces of two cells, one above the other, from the cell at one vertical edge of one to that at the other of the other. Hybrid-diagonal piece are bound to a third of the board, but all this game's compounds except the Sheikh and Tricorn have an unbound component. The Rumbaba moves one step along hybrid diagonals. The Rudder moves one or two steps along tbe same hybrid diagonal. The Dicorn moves any distance along tbe same hybrid diagonal through empty intermediate cells. The Rumchick moves one step along either of the two hybrid diagonals most directly toward the face of the board furthest from its starting cell.

Apart from the Ayatollah, and possible promotee Dictators, both of which use all three kinds of diagonal but not orthogonals, the armies have entirely different pieces:

Represented byArmy 1Army 2Army 3number aside
KingEMPEROR (Er) General+Ferz+ViceroyPRESIDENT (Pd) General+Ferz+RumbabaFOUNDER (Fd) General+Viceroy+Rumbaba1
Promoted WingEMPRESS (Es) Rook+Bishop+UnicornFIRSTLADY (Fl) Rook+Bishop+DicornSUFFRAGETTE (Sf) Rook+Unicorn+Dicorn1
RookMARCHIONESS (Ms) Rook+DicornDUCHESS (Ds) Rook+UnicornQUEEN (Qn) Rook+Bishop2
BishopGOVERNOR (Gv) Bishop+UnicornPONTIFF (Pf) Bishop+DicornTRICORN (Tn) Unicorn+Dicorn2
WingSULTAN (Sn) Wazbaba+Fearful+VinnockEMIR (Ei) Wazbaba+Fearful+RudderMOGUL (Mg) Wazbaba+Vinnock+Rudder2
HelmAYATOLLAH (Ay) Fearful+Vinnock+RudderAYATOLLAH (Ay) Fearful+Vinnock+RudderAYATOLLAH (Ay) Fearful+Vinnock+Rudder2
GoldMAHDI (Md) Wazbaba+RudderKHAN (Kh) Wazbaba+VinnockPASHA (Pa) Wazbaba+Fearful4
SilverIMAM (Im) Fearful+VinnockMULLAH (Mu) Fearful+RudderSHEIKH (Sk) Vinnock+Rudder4
PointPAWNBROKER (Po) noncapturing as Point,
capturing as Cross+Saltire
PAWNBREAKER (Pe) noncapturing as Point,
capturing as Cross+Rumchick
BROKERBREAKER (Bb) noncapturing as Point,
capturing as Saltire+Rumchick
The DICTATOR, Bishop+Unicorn+Dicorn, is not an array piece, but is sometimes available through promotion.


Every kind of Pawn analogue has an optional double-step noncapturing move from its starting cell. An enemy Pawn analogue can, if in the right position in terms of its own capturing moves, immediately capture it En Passant as if it had made only the single-step move.

Castling is between the King analogue and the piece three levels above it. This is included as it is possible to open up the centre levels in a FIDE-like way to bring out a Queen and Bishop analogue, and so logical to bring a Rook analogue into the area and take the King one out of it.

When a symmetric piece is captured it goes into a neutral Reserve of captured pieces.

A Pawn analogue reaching the far face of the board must be promoted. If there are pieces in the Reserve it must be promoted to such a piece, converted to the same army as the Pawn analogue. If there aren't it is promoted to Dictator, which is represented by flipping. Once such a promotee is captured it goes into the Reserve permanently promoted, allowing a later promotion to Dictator even when there are other (particularly short-range) pieces in the Reserve. Note that the disadvantage of a Brokerbreaker not being promotable when it has only a noncapturing move counters the advantage that all its capturing moves bring it forward two ranks.

Despite the Shogi representation no other piece can be promoted.

A player is Checkmated when their Emperor, President, or Founder is threatened by the player about to move, and that piece is removed. Given the initial piece density of 40% and lack of reintroduction of pieces other than as promotion, the rest of the Chechmated army is let in placecomplete with move and physical orientation. Pawn analogues also retain movement orientation, promotion zone, and choice of promotee pieces. Whichever of the two remaining players Checkmates the other wins.

This 'user submitted' page is a collaboration between the posting user and the Chess Variant Pages. Registered contributors to the Chess Variant Pages have the ability to post their own works, subject to review and editing by the Chess Variant Pages Editorial Staff.

By Charles Gilman.
Web page created: 2011-03-26. Web page last updated: 2011-08-04